The researchers created a cheap code cracking device from off the shelf Field Programmable Gate Array hardware, to brute force attack the 40 bit keyspace. They wrote software to simulate the radio protocols of the RFID tokens on a laptop computer connected to radio equipment.

These tokens do not use modern strong cryptography, such as the AES algorithm, but the attack demonstration (including online videos) should be seen as a dire warning for the likes of Tesco, WalMart or the US Department of Defense who seem to be set to use billions of far less sophisticated yet still re-programmable RFID tags e.g. EPC Class 1 Generation 1 or Generation 2 tags, which do not use any encryption at all !

It also has implications for the privacy and security of new USA Biometric Passport for which it is also planned to use unencrypted RFID chips.